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(N0 M-odeL s. R. WILMOT.

METHOD OF MAKING PLATTENED TUBES. I No. 408.059. Patented July 30, 1

N. PETERS. Phmvumngmr ar. Washing mmmm c UNITED STATES PATENT OFFICE.

SAMUEL R. IVILMOT, OF BRIDGEPORT, CONNECTICUT, ASSIGNOR TO THE \VILMOT & HOBBS MANUFACTURING COMPANY, OF SAME PLACE.

METHOD OF MAKING FLATTENED TUBES.

SPECIFICATION formingpart of Letters Patent No. 408,059, dated July 30, 1889.

Application filed January 28, 1889. Serial No. 297,759. (No model.)

To all whom it may concern: drawings in producing a tube closed at one Be it known that I, SAMUEL R. lViLMOT, a end. Fig. 2 is an elevation, partly in section, citizen of the United States, residing at of the die and punch which punch out the Bridgeport, in the county of Fairiield and bottom of the drawn tube; Fig. 3, a section 5 State of Connecticut, have invented an Imof the dies whichflatten the drawn tube; Fig. proved Method of Forming Flattcned Tubes; 4, an elevation of the punch and section of and I do hereby declare the following to be a the die, which act together to draw the flatfull, clear, and exact description of the intened tube; and Fig. 5, an elevation of a comvention, such as will enable others skilled in pleted drawn flattened tube. [o the art to which it appertains to make and 1 denotes a disk of metal. In the present use the same. instance I have illustrated my invention as My invention has for its object to devise a applied to the drawing of flattened padlocknovel method of forming flattened tubes. It cases, the disk for this purpose being a disk is frequently and for many pu rposcs required of what is known as f mild steel. This disk 6 5 15 in the arts to use flattened tubes of steelas, is drawn into a round tube in precisely the for example, in the manufacture of a certain same manner that cartridge-shells are drawn, class of padlock-cases where the greatest at the results of three drawings being indicated tainable accuracy is required. It is further by dotted lines in Fig. 1. more desirable that these cases should be I In Fig. 2, 2 denotes the drawn tube, which 2o drawn rather than cast or forged, drawn shown in section; 3, a punch the body of work of this class being superior in every rewhich just passes within the tube, and which spect and very much cheaper to produce. It is provided with a reduced central portion 4 has, however, up to the time of my present which punchesout the bottom of the drawn invention been an utter impossibility to draw tube. 2 5 flattened tubes of steel that could be used in 5 denotes a die having a central opening 6, fine work. Attempts without number have which receives the central portion 4. of punch been made to produce flattened tubes having 3, said opening being enlarged slightly at the rounded ends by the operation of drawing bottom to permit the pnnchedout portion to fromadisk. It has never been accomplished, drop away freely, said die also having a 0 however, satisfactorily, in steel. It follows, countersink in its upper side to receive the inevitably, that the greatest portion of the lower end of the tube and the body of the drawing operation must take place at the punch, while the reduced central portion rounded ends of the tubes, and even if a punches out the bottom, thereby Leaving a disk of sufficient size were taken to give the flange 10 at the lower end of the tube. 8; 5 right height at the side and allow for the In Fig. 3, 8 represents upper and lower flatnecessary waste at the ends, it was found imtelling-dies, which are exactly alike. The possible to produce pefect tubes, as the tubes next operation, after punching out the bottom invariably cracked on the surface at the of the round-drawn tube, is to place a core 9 points where the endsof the curves joined the within the tube. The ends of this core are 0 4o flat portions at the sides of the tubes. These rounded to correspond with the curvature of objections I am enabled to obviate entirely the tube, and its upper and lower sides are by my novel method and to produce perfect flattened, as shown in Fig. 3. The thickdrawn flattened tubes from steel at very ness of this core is practically the same as slight expense. the required diameter of the completed ar- 45 In order that others may understand my ticle. The coreis placed in the tube, as shown novel method, I will proceed to describe the in Fig. 3, its bottom resting against the flange same, referring bynumbers to the aecompany- 10, which is left at the outer edge of the boting drawings, forming part of this specificatom of the tube when the central portion of tion, in whichthe bottom is punched out by the reduced Ice 50 Figure 1 is an edge view of a disk of metal, portion of the die, as already described. Havindicating in dotted lines the results of three in g placed the round tube, with the core within it, between the flattened dies 8, as shown in Fig. 3, said dies are closed together and act to flatten out the tube to correspond with the dimensions of said dies. This operation leaves the tube in substantially the shape required, although an additional drawing operation is required to give to the flattened tube the accuracy and perfection of finish required in the special use referred to, it being essential that the thickness of the tube and the dimensions thereof be uniform at all parts.

11 denotes a flattened punch which is now passed within the flattened tube, the bottom resting upon flange 10.

12 is a drawing-die corresponding substantially with punch 11. The flattened tube, after being removed from dies 8, and the core, is placed upon punch 11, and is then forced down through drawing-die 12, which acts to give it the final drawing operation,and leaves the flattened tube perfectly smooth and finished and wholly free from cracks in the surface.

13 denotes strippers under die 12, which act to remove the drawn flattened tube from punch 11. This operation completes the formation of the flattened tube with the exception of trimming the ends, it being understood of course that the removal of the drawn tube from punch 11 and the trimming of the ends of the completed tube have nothing to do with my present invention.

I claim- The method of forming flattened tubes, which consists in drawing a round tube from a disk of metal in the usual manner, then punching the bottom from said tube, leaving an inwardly turned flange, then flattening said rounded tube to substantially the shape required, and finally placing the flattened tube upon a correspondingly-flattened punch, the end of said punch resting against said flange, and then forcing said tube through a correspondinglyshaped drawing-die, substantially as described.

In testimony whereof I aflix my signature in presence of two witnesses.

SAMUEL R. WVILMOT.

Witnesses:

A. M. Woos'rER, ETTA F. PETTIT. 

